Abstract:
Energy harvesting offers a promising alternative to solve the
sustainability limitations arising from battery size constraints in
sensor networks. Several considerations in using an environmental
energy source are fundamentally different from using
batteries. Rather than a limit on the total energy, harvesting
transducers impose a limit on the instantaneous power
available. Further, environmental energy availability is often
highly variable and a deterministic metric such as residual battery
capacity is not available to characterize the energy source. The
different nodes in a sensor network may also have different energy
harvesting opportunities. Since the same end-user performance may be
achieved using different workload allocations at multiple nodes, it
is important to adapt the workload allocation to the spatio-temporal
energy availability profile in order to enable energy-neutral
operation of the network. This paper describes power management
techniques for such energy harvesting sensor networks. Platform
design considerations as well as power scaling techniques at the
node-level and network-level are described.